4-(Substituted)pteridines, analogues of kinetin

1967 ◽  
Vol 45 (19) ◽  
pp. 2213-2216 ◽  
Author(s):  
Rodney F. Lloyd ◽  
Charles G. Skinner ◽  
William Shive
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Biological Systems ◽  
Imidazole Ring ◽  
Lettuce Seed ◽  
Structural Specificity ◽  
Lettuce Seed Germination ◽  
Purine Ring

Studies on the structural specificity of kinetin have demonstrated that a variety of 6-(substituted)aminopurines and 6-(substituted)thiopurines, even with an additional 2-fluoro or 2-amino substituent, replace kinetin in several biological systems. It was of considerable interest to investigate further the specificity of the imidazole ring by preparing a group of 4-(substituted)pteridines. That the pteridine ring cannot replace the purine ring with retention of activity is indicated by the inactivity of these compounds in stimulating the rate of lettuce seed germination either in the presence or in the absence of gibberellic acid.

scholarly journals Action of Gibberellic Acid on Lettuce Seed Germination

1960 ◽  
Vol 35 (5) ◽  
pp. 557-566 ◽  
Author(s):  
Hiroshi Ikuma ◽  
Kenneth V. Thimann
Keyword(s):  
Seed Germination ◽  
Gibberellic Acid ◽  
Lettuce Seed ◽  
Lettuce Seed Germination

scholarly journals Preventing thermoinhibition in a thermosensitive lettuce genotype by seed imbibition at low temperature

2003 ◽  
Vol 60 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Warley Marcos Nascimento
Keyword(s):  
Seed Germination ◽  
Low Temperature ◽  
High Temperatures ◽  
Lactuca Sativa ◽  
Lettuce Seed ◽  
Temperature Dependent ◽  
Lettuce Seeds ◽  
Lactuca Sativa L ◽  
Lettuce Seed Germination ◽  
Dark Green

Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.

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